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Hazardous Waste Objective: I will evaluate and describe effective means of managing and disposing hazardous waste.

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Presentation on theme: "Hazardous Waste Objective: I will evaluate and describe effective means of managing and disposing hazardous waste."— Presentation transcript:

1 Hazardous Waste Objective: I will evaluate and describe effective means of managing and disposing hazardous waste.

2 Core Case Study: Love Canal — There Is No “ Away ” Between 1842-1953, Hooker Chemical sealed multiple chemical wastes into steel drums and dumped them into an old canal excavation (Love Canal). In 1953, the canal was filled and sold to Niagara Falls school board for $1. The company inserted a disclaimer denying liability for the wastes.

3 Core Case Study: Love Canal — There Is No “ Away ” In 1957, Hooker Chemical warned the school not to disturb the site because of the toxic waste. – In 1959 an elementary school, playing fields and homes were built disrupting the clay cap covering the wastes. – In 1976, residents complained of chemical smells and chemical burns from the site.

4 Core Case Study: Love Canal — There Is No “ Away ” President Jimmy Carter declared Love Canal a federal disaster area. – The area was abandoned in 1980 (left). Figure 22-1

5 Core Case Study: Love Canal — There Is No “ Away ” It still is a controversy as to how much the chemicals at Love Canal injured or caused disease to the residents. Love Canal sparked creation of the Superfund law, which forced polluters to pay for cleaning up abandoned toxic waste dumps.

6 HAZARDOUS WASTE Hazardous waste: is any discarded solid or liquid material that is toxic, ignitable, corrosive, or reactive enough to explode or release toxic fumes. – The two largest classes of hazardous wastes are organic compounds (e.g. pesticides, PCBs, dioxins) and toxic heavy metals (e.g. lead, mercury, arsenic).

7 Fig. 22-15, p. 534 What Harmful Chemicals Are in Your Home? Glues and cements Dry-cell batteries (mercury and cadmium) Rust inhibitor and rust remover Brake and transmission fluid General Cleaning Battery acid Wood preservatives Stains, varnishes, and lacquers Automotive Gasoline Used motor oil Paint Latex and oil-based paints Paint thinners, solvents, and strippers Gardening Pesticides Weed killers Ant and rodent killers Antifreeze Flea powders Disinfectants Septic tank cleaners Spot removers Drain, toilet, and window cleaners Artist paints and inks Solvents

8 Hazardous Waste Regulations in the United States Two major federal laws regulate the management and disposal of hazardous waste in the U.S.: – Resource Conservation and Recovery Act (RCRA) Cradle-to-the-grave system to keep track waste. – Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) Commonly known as Superfund program.

9 Hazardous Waste Regulations in the United States The Superfund law was designed to have polluters pay for cleaning up abandoned hazardous waste sites. – Only 70% of the cleanup costs have come from the polluters, the rest comes from a trust fund financed until 1995 by taxes on chemical raw materials and oil.

10 DEALING WITH HAZARDOUS WASTE We can produce less hazardous waste and recycle, reuse, detoxify, burn, and bury what we continue to produce. Figure 22-16

11 Fig. 22-16, p. 536 Ocean and atmospheric assimilation Produce Less Waste Recycle and reuse Convert to Less Hazardous or Nonhazardous Substances Manipulate processes to eliminate or reduce production Land treatment Landfill Incineration Thermal treatment Put in Perpetual Storage Underground injection Waste piles Surface impoundments Salt formations Arid region unsaturated zone Chemical, physical, and biological treatment

12 Conversion to Less Hazardous Substances Physical Methods: using charcoal or resins to separate out harmful chemicals. Chemical Methods: using chemical reactions that can convert hazardous chemicals to less harmful or harmless chemicals.

13 Conversion to Less Hazardous Substances Biological Methods: – Bioremediation: bacteria or enzymes help destroy toxic and hazardous waste or convert them to more benign substances. – Phytoremediation: involves using natural or genetically engineered plants to absorb, filter and remove contaminants from polluted soil and water.

14 Phytostabilization Plants such as willow trees and poplars can absorb chemicals and keep them from reaching groundwater or nearby surface water. Rhizofiltration Roots of plants such as sunflowers with dangling roots on ponds or in green- houses can absorb pollutants such as radioactive strontium-90 and cesium-137 and various organic chemicals. Phytoextraction Roots of plants such as Indian mustard and brake ferns can absorb toxic metals such as lead, arsenic, and others and store them in their leaves. Plants can then be recycled or harvested and incinerated. Phytodegradation Plants such as poplars can absorb toxic organic chemicals and break them down into less harmful compounds which they store or release slowly into the air. Inorganic metal contaminants Organic contaminants Radioactive contaminants Brake fern Poplar tree Indian mustard Willow tree Sunflower Oil spill Landfill Groundwater Soil Polluted leachate Decontaminated water out Polluted groundwater in Groundwater Soil

15 Conversion to Less Hazardous Substances Incineration: heating many types of hazardous waste to high temperatures – up to 2000 °C – in an incinerator can break them down and convert them to less harmful or harmless chemicals.

16 Conversion to Less Hazardous Substances Plasma Torch: passing electrical current through gas to generate an electric arc and very high temperatures can create plasma. – The plasma process can be carried out in a torch which can decompose liquid or solid hazardous organic material.

17 Fig. 22-19, p. 538 Advantages Trade-Offs Plasma Arc Small High cost Produces no toxic ash Can vaporize and release toxic metals and radioactive elements Can release particulates and chlorine gas Mobile. Easy to move to different sites Produces CO2 and CO Disadvantages

18 Long-Term Storage of Hazardous Waste Hazardous waste can be disposed of on or underneath the earth ’ s surface, but without proper design and care this can pollute the air and water. – Deep-well disposal: liquid hazardous wastes are pumped under pressure into dry porous rock far beneath aquifers. – Surface impoundments: excavated depressions such as ponds, pits, or lagoons into which liners are placed and liquid hazardous wastes are stored.

19 Fig. 22-20, p. 539 Safe method if sites are chosen carefully Trade-Offs Deep Underground Wells AdvantagesDisadvantages Encourages waste production Existing fractures or earthquakes can allow wastes to escape into groundwater Leaks from corrosion of well casing Leaks or spills at surface Low cost Easy to do Wastes can be retrieved if problems develop

20 Fig. 22-21, p. 539 Low construction costs Can store wastes indefinitely with secure double liners Groundwater contamination from leaking liners (or no lining) Trade-Offs Surface Impoundments Advantages Promotes waste production Disruption and leakage from earthquakes Overflow from flooding Air pollution from volatile organic compounds Wastes can be retrieved if necessary Can be built quickly Low operating costs Disadvantages

21 Long-Term Storage of Hazardous Waste Long-Term Retrievable Storage: Some highly toxic materials cannot be detoxified or destroyed. Metal drums are used to stored them in areas that can be inspected and retrieved. Secure Landfills: Sometimes hazardous waste are put into drums and buried in carefully designed and monitored sites.

22 Secure Hazardous Waste Landfill In the U.S. there are only 23 commercial hazardous waste landfills. Figure 22-22

23 Fig. 22-22, p. 540 Bulk waste Gas vent Topsoil Earth Plastic cover Clay cap Double leachate collection system Plastic double liner Impervious clay cap Leak detection system Reactive wastes in drums Groundwater monitoring well Groundwater Water table Earth Impervious clay Sand

24 Fig. 22-23, p. 540 What Can You Do? Use pesticides in the smallest amount possible. Use less harmful substances instead of commercial chemicals for most household cleaners. For example use liquid ammonia to clean appliances and windows; vinegar to polish metals, clean surfaces, and remove stains and mildew; baking soda to clean household utensils, deodorize, and remove stains; borax to remove stains and mildew. Do not dispose of pesticides, paints, solvents, oil, antifreeze, or other products containing hazardous chemicals by flushing them down the toilet, pouring them down the drain, burying them, throwing them into the garbage, or dumping them down storm drains. Hazardous Waste

25 Case Study: Lead Lead is especially harmful to children and is still used in leaded gasoline and household paints in about 100 countries. Figure 22-24

26 Fig. 22-24, p. 541 Phase out leaded gasoline worldwide Solutions Prevention Lead Poisoning Control Wash fresh fruits and vegetables Test existing candles for lead Test for lead in existing ceramicware used to serve food Remove lead from TV sets and computer monitors before incineration or land disposal Remove leaded paint and lead dust from older houses and apartments Replace lead pipes and plumbing fixtures containing lead solder Ban candles with lead cores Ban lead glazing for ceramicware used to serve food Ban use of lead in computer and TV monitors Ban use of lead solder Test blood for lead by age 1 Phase out waste incineration Sharply reduce lead emissions from old and new incinerators

27 Case Study: Mercury Mercury is released into the environment mostly by burning coal and incinerating wastes and can build to high levels in some types of fish. Figure 22-26

28 Fig. 22-26, p. 543 Solutions Mercury Pollution Phase out use of mercury in all products unless they are recycled Require labels on all products containing mercury Switch from coal to natural gas and renewable energy resources such as wind, solar cells, and hydrogen Convert coal to liquid or gaseous fuel Collect and recycle mercury-containing electric switches, relays, and dry-cell batteries Tax each unit of mercury emitted by coal-burning plants and incinerators Sharply reduce mercury emissions from coal-burning plants and incinerators PreventionControl Remove mercury from coal before it is burned Phase out waste incineration

29 Fig. 22-25, p. 542 BIOMAGNIFICATION IN FOOD CHAIN SEDIMENT PRECIPITATION WINDS AIR WATER Inorganic mercury and acids (Hg 2+ ) Inorganic mercury and acids (Hg 2+ ) Organic mercury (CH 3 Hg + ) Inorganic mercury (Hg 2+ ) Hg 2+ and acids Runoff of Hg 2+ and acids Large fish Small fish ZooplanktonPhytoplankton Hg and SO 2 Hg 2 + and acids Human sources Incinerator Coal- burning plant Elemental mercury vapor (Hg) Photo- chemical Oxidation Elemental mercury liquid (Hg) Deposition Bacteria and acids Settles out Settles out Settles out Vaporization Deposition

30 ACHIEVING A LOW-WASTE SOCIETY In the U.S., citizens have kept large numbers of incinerators, landfills, and hazardous waste treatment plants from being built in their local areas. Environmental justice means that everyone is entitled to protection from environmental hazards without discrimination.


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